In the design and construction of corrugated board cartons and containers, it is common practice to provide for the carton to be collapsible. That is to say, the carton is capable of being in a flat, non-usable condition and movable by certain manipulations to an erected, usable condition, in which condition it can be used for the purpose for which it is intended. One type of carton which is particularly useful is the type shown and described in the patent of Paige, U.S. Pat. No. 4,325,493 in which two shells are telescopingly arranged relative to one another and are joined by strips which ultimately become the bottom of the erected carton. Other patents or Paige which show this type of carton are U.S. Pat. Nos. 2,577,588; 2,843,308; 3,278,108; 3,430,840; and 4,406,380. Attempts have been made in the past to improve the construction shown in these patents in such a way that the resulting carton is not only stronger but also can be made by a straight-through operation. In other words, the desirable situation would be one in which the carton blank passes continuously in a single direction through a machine for constructing corrugated board cartons. These and other difficulties of the prior art have been obviated in a novel manner by the present invention.
It is, therefore, an outstanding object of the invention to provide a carton having two telescoping shells with strips joining them that ultimately form the bottom of the carton, wherein the bottom thus formed is very strong.
Another object of this invention is the provision of a carton of the telescoping shell-type which can be manufactured by a continuous straight movement through a manufacturing machine.
A further object of the present invention is the provision of a carton of the telescoping shell-type that permits a straight-through manufacturing operation in which the carton blank is not turned.
It is another object of the instant invention to provide a carton of the telescoping shell-type which is simple in construction, which is inexpensive to manufacture, and which is capable of a long life of useful service.
Another object of the invention is the provision of a telescoping-type carton which can be manufactured by introducing the blank to a carton-making machine without prior operations and is a continuous movement in which the blank is neither stopped nor turned.
With these and other objects in view, as will be apparent to those skilled in the art, the invention resides in the combination of parts set forth in the specification and covered by the claims appended hereto.